Alex Byrne makes a normative claim in his book Transparency And Self-Knowledge, that the epistemic rule for self-knowledge of belief BEL (if P, believe that you believe that P), is a good rule. In this thesis, by utilizing both philosophical writings and empirical studies in psychology I reject Byrne’s claim that BEL is a good rule. More specifically, I argue that many cases of implicit biases are essentially beliefs, because they share many characteristics that are paradigmatic to beliefs. Then I argue that applying BEL, as a method of obtaining self-knowledge of beliefs, not only fails to discover many of our implicit biases, but also gives wrong verdict for many of our implicit biases. Finally, I conclude that BEL is not a good rule, and any good method for obtaining self-knowledge of belief should not ignore the importance of observing one’s own behaviors.